Abstract: A shaft seal comprising a plurality of members which collectively engage the shaft exterior in substantially uninterrupted 360.degree. sealing contact in a plane perpendicular to the axis of the shaft while providing relatively high capacity for wear using nonflexible materials such as graphite. The provision of 360.degree. contact in a single plane enables engagement between the shaft seal and the shaft to be limited to a single ring structure, rather than requiring a pair of rings in side-by-side abutting relation. The seal members comprise a plurality of followers and an equal plurality of drivers, with each of the members being movable inwardly as it wears. Each of the followers is driven inwardly by drivers on each side as it wears. Each follower has a wear surface configured for sealing engagement with the shaft, and a pair of bearing surfaces for engagement with drivers on either side.

Abstract: A first wall structure for use in a fusion device surrounds the plasma region and includes a base wall which is substantially continuous. The base wall has an inner surface which faces the plasma region and an outer surface which faces the first wall coolant. The inner surface has a plurality of recesses. The wall structure also includes a number of inserts corresponding in number to the recesses with each insert being received in a respective recess and extending inwardly beyond the inner base wall surface. The inserts are made of material having a substantially greater heat flux capability than the material from which the base wall is formed. A method of forming a composite first wall structure for use in a fusion device, is also disclosed.

Abstract: A thermodynamic power cycle and engine for motive power is disclosed which uses a condensible working fluid such as water in which the pressurized fluid, after being heated to vapor, is expanded to perform work in two or more stages with low expansion ratios per stage. The working fluid is reheated between one or more of the expansion stages with short reheats having high average heat addition temperatures. For use with a positive-displacement expander, the fluid has suspended in it a finely-divided powdered lubricant, such as calcium difluoride, which is used to lubricate all wear surfaces. After the fluid leaves the expander, it is still superheated and is desuperheated prior to condensing by transferring its energy to the combustion chamber inlet air. This air preheating reduces the fuel quantity required and facilitates the use of difficult-to-burn fuels such as coal dust. The combustion of the fuel and air preferably proceeds to two steps: the first overly rich and the second very lean.